An automated external defibrillator (AED) system includes shock generating electronics, a battery configured for providing power to the shock generating electronics, power management circuitry configured for controlling the shock generating electronics and the battery, and a controller configured for controlling the power management circuitry. The AED system is housed in a small enclosure that provides a hand-carryable device, and the enclosure includes an externally mounted clip that enables the device to be wearable on a user's belt. Cardiac pads are stored separately and are plugged into the device to automatically power on the device. An associated AED method is designed for a trained user to operate the AED system.